X-rays are used in oil and gas field tools for a variety of different applications. In one example, X-rays are used to evaluate a substance, such as a fluid or a formation. To this end, an X-ray generator is used to generate X-rays that pass through the substance. At least some of the X-rays that pass through the substance are measured by an X-ray detector. The resulting signals from the X-ray detector can be used to determine substance characteristics, such as density, porosity and/or photo-electric effect.
X-rays with energies over 100 keV can be generated using a variety of methods. In one method, X-rays are generated by accelerating electrons within a particle accelerator and striking the electrons against a target. In above-ground systems, conventional RF amplification devices are commonly used to drive acceleration of the charged particles within the particle accelerator. Examples of such conventional RF amplification devices include klystron tubes, travelling wave tubes, magnetrons, gyrotrons and other vacuum power devices.
Such conventional RF amplification devices do not perform reliably in high temperatures and dynamic temperatures environments. High temperatures and dynamic temperatures are common in borehole environments (e.g., 175° C. and above). Accordingly, the conventional RF amplification devices are not sufficiently reliable for use in oil and gas field tools. Also, many such conventional RF amplification devices occupy a large amount of space. Large spacing requirements are particularly disadvantageous in borehole tools where available space is scarce.